Quantum Communication in a Curved Spacetime

By:

B. Nasr

Department of Physics, University of Isfahan

Quantum entanglement• “Spooky action at a distance” Albert Einstein• 1953; Einstein, Podolsky, Rosen introduced the

EPR paradox• The result of a measurement performed on one

part of a quantum system can have an instantaneous effect on the result of a measurement performed on another part, regardless of the distance separating the two parts

• Known as "nonlocal behaviour" or "quantum weirdness"

• Relativistic Quantum Information Theory• Classically:

• In Relativistic QM:

• In a Curved Spacetime:

|σ

,p σ

( ), ;p x xσ

Spin in Curved Spacetime

Spin decoherence around a Schwarzschild black hole

Circular motion:

→

22 2 2 2 2 2 211

( sin )s

s

rr r

r

drds c dt r d dθ θ φ⎛ ⎞⎜ ⎟ ⎛ ⎞⎝ ⎠

⎜ ⎟⎝ ⎠

−−

=− + + +Schwarzschild →

→